ABSTRACT
The fluid flow through bluff bodies (e.g., cylinders of circular and non-circular cross-sections, etc.) has been the topic of intense research for a century or so because of its importance in various engineering applications such as electronic cooling, heat exchange systems, cooling towers, design of vortex flow meters and flow dividers, etc. In spite of such wide applications, heat transfer around these obstacles has been simulated only by a few researchers in the unsteady flow regime. Above critical Reynolds number, the flow becomes unsteady and periodic. This has motivated us to simulate the heat transfer over an obstacle of triangular crosssection in an unconfined space.
In order to simulate this situation, the computational grid is created by using commercial grid generator GAMBIT. The numerical computations are carried out by using FLUENT for Reynolds numbers of 100 and 130 for the working fluid as air. The SIMPLE method is used to solve the Navier-Stokes and energy equations. The second order upwind scheme is used to discretize the convective terms, while the central difference scheme is used to discretize the diffusive terms in the governing equations. The average Nusselt number is obtained by averaging it over certain fixed number of cycles. The results are compared well with the literature values. The temperature isotherms are also plotted for above range of conditions.
Keywords: Triangular cylinder, Unsteady regime,
Reynolds number, Nusselt number.
